1. Field of the Disclosure
The present invention relates to a coring system including a tensiometer and a method of determining accurate boring using the same.
2. Description of the Related Art
There have been developed many coring rigs for studying underground resources or observing the history and the environmental change of the earth.
Most coring rigs place a coring part with a core for carrying an object to be cored, on the bottom of the sea or the bottom of a river and then insert it into a sediment, using the gravity etc. When the coring part is inserted in the sediment, some of the sediment comes into the core, and a sample of the sediment is obtained by returning the coring part.
However, because the coring part is inserted deep in the bottom of the sea or the bottom of a river in most cases of coring, there is a problem in that it is difficult to know whether the coring part is inserted in a sediment while keeping vertical.
When a coring part is not vertically inserted in a sediment, there is a problem in that the position (depth) of the expected sample in the sediment and the position (depth) of the actually obtained sample in the sediment become different.
FIG. 1 shows a case when a coring part is accurately inserted in a sediment while keeping vertical and FIG. 2 shows a case when a coring part is inaccurately inserted at a angle in the bottom of the sea.
The same amount of samples of the sediment remains in the cores of the coring parts in both of FIGS. 1 and 2. In those cases, however, the positions (depths) of the samples in the sediments are different and it causes an error in investigation of changes in composition to the depth of the sediment.